Various types of compression mechanisms such as scroll type, swing type, and rolling piston type (i.e., rotary type) have been employed in conventional rotating compressors. Such a rotating compressor is used to compress a refrigerant gas in a refrigerating apparatus (e.g., an airconditioner) which executes a refrigerating cycle, as set forth for example in Japanese Patent Kokai No. (2000)97183. A compressor motor, housed in the rotating compressor, serves as a drive source for activating a compression mechanism of the scroll, swing, or rolling piston type.
Here, referring to a scroll compressor (100) of FIG. 10 as an example, a general structure of a conventional rotating compressor will be described below.
The scroll compressor (100) is made up of a casing (101), a compressor motor (102), and a compression mechanism (103). The casing (101) is made up of a trunk part (104) shaped like a cylinder and end plates (105, 106) secured firmly, by welding, to an upper and lower ends of the trunk part (104), respectively. The compressor motor (102) is made up of a stator (107) secured firmly to the trunk part (104) and a rotor (108) disposed on the inner peripheral side of the stator (107). A drive shaft (109) is coupled to the rotor (108).
The compression mechanism (103) has a fixed scroll, an orbiting scroll, and a housing all of which are not shown in the Figure, and the housing is secured firmly to the casing. In some cases, the fixed scroll is secured firmly to the casing. Additionally, the drive shaft (109) projects above and below the stator (107) and the rotor (108). An upper end of the drive shaft (109) is connected to the orbiting scroll. On the other hand, a lower end of the drive shaft (109) is supported, through a bearing member (110), on the casing (101). Operations of the orbiting scroll accompanying the rotation of the drive shaft (109) cause variations in volume of a compression chamber, whereby the compression mechanism (103) performs operations of sucking, compressing, and discharging a refrigerant gas.
In the scroll compressor (100), the housing of the compression mechanism (103) is close-fitted, at its outer peripheral part, to the casing (101), thereby defining spaces separated from each other, i.e., a space above the compression mechanism (103) and another below the compression mechanism (103), as set forth for example in Japanese Patent Kokai No. (1999)22661. In the example diagrammed, the lower space is a high-level pressure space, while the upper space is a low-level pressure space. These spaces are sealed off from each other at a joint area (111) between the casing (101) and the housing. In such an arrangement, the housing functions as a partition member.